The presence of perchlorate (ClO(4) (-)) in some U.S. drinking water supplies has raised concern about potential adverse thyroidal health effects, because ClO(4) (-) is known to competitively inhibit iodide uptake at the sodium iodide symporter (NIS). Humans are nutritionally and environmentally exposed to other competitive inhibitors of iodide uptake, including thiocyanate (SCN(-)) and nitrate...

Cell surface proteins of normal and neoplastic lymphocytes were labeled with iodide-(125)I by lactoperoxidase-catalyzed iodination. Incubation of (125)I-labeled iodide cells in vitro resulted in the release of iodinated surface proteins at a rapid rate which was dependent on cellular respiration and protein synthesis. Comparisons by disc electrophoresis showed a marked similarity between urea-s...

Perchlorate blocks thyroidal iodide transport in a dose-dependent manner. The human sodium/iodide symporter (NIS) has a 30-fold higher affinity for perchlorate than for iodide. However, active transport of perchlorate into thyroid cells has not previously been demonstrated by direct measurement techniques. To demonstrate intracellular perchlorate accumulation, we incubated NIS-expressing FRTL-5...

UNLABELLED Transfer of the human sodium iodide symporter (hNIS) has been proposed as a new principle of cancer gene therapy. This study evaluates the iodide kinetics and dosimetry of iodide in hNIS-expressing thyroid carcinoma cells under optimized conditions. METHODS Using a bicistronic retroviral vector for the transfer of the hNIS and the hygromycin resistance gene, hNIS-expressing rat thy...

The formation of tissue iodoproteins during the peripheral metabolism of the thyroid hormones was examined by determining the concentration of nonethanol-extractable (125)I (NE(125)I) in various tissues after the intravenous injection of 3,5,3'-triiodo-L-thyronine (T3-(125)I) and L-thyroxine-(125)I (T4-(125)I) in groups of rats with iodide-blocked thyroid glands. 3 days after T3-(125)I and 7 da...

Prostate cancer is one of the most promising candidates for sodium iodide symporter (NIS)-mediated gene therapy. Adenovirus-mediated expression of NIS that is driven by prostate-specific promoters induces generous radioiodine accumulation in prostate cancer cells that may be used for therapy with (131)I. We have recently developed a replication-deficient adenovirus carrying the human NIS cDNA l...

Triiodothyronine and thyroxine induce a 3-fold increase in the rate of growth of GH(1) cells in culture. To study further the action of these hormones, we examined the binding of [(125)I]triiodothyronine and purified [(125)I]thyroxine to cellular fractions after incubation with intact cells in serum-free medium. High-affinity, low-capacity binding sites for the hormones were demonstrated in nuc...

Radioiodine is a routine therapy for differentiated thyroid cancers. Non-thyroid cancers may be treated with radio-iodine following transfection with the human sodium/iodide symporter (hNIS) gene. The glial fibrillary acidic protein (GFAP) promoter is an effective tumor-specific promoter for gene expression and thus may be useful in targeted gene therapy of malignant glioma. The present study u...

An enzymatic iodination procedure utilizing lactoperoxidase (LPO), radioactive iodide, and hydrogen peroxide generated by a glucose oxidase-glucose system has been described and utilized for a study of the red cell membrane. 97% of the incorporated isotope is in the erythrocyte ghost and 3% is associated with hemoglobin. No significant labeling of the red cell membrane occurs in the absence of ...